CODEWITHSUNDEEP
c#asp.net-mvcasp.net-mvc-3
John
John

Reputation: 3945

if record exists delete it?

I am using this code to create a record in the ClientAccountAccess table. However there should only ever be one record in this table at any time. so if this function is called I first want to check if a record exists, if it does delete it then add the new record.

     private static void SetAccessCode(string guidCode)
        {
            using (EPOSEntities db = new EPOSEntities())
            {

//so here would I say something like (see below)

                ClientAccountAccess client = new ClientAccountAccess();
                client.GUID = guidCode;
                db.AddToClientAccountAccesses(client);
                db.SaveChanges();
            }
        }

//
ClientAccountAccess clientAccessCodes = db.ClientAccountAccesses
                    .OrderByDescending(x => x.Id)
                    .Take(1)
                    .Single();

                if clientAccessCodes.exists()

                    db.DeleteObject(clientAccessCodes);
                db.SaveChanges();

Upvotes: 1

Views: 1191

Answers (2)

Arion
Arion

Reputation: 31239

Do you really need to remove it? If you don't you can do this:

private static void SetAccessCode(string guidCode)
{
    using (EPOSEntities db = new EPOSEntities())
    {
        var c= db.ClientAccountAccesses.FirstOrDefault(f=>f.GUID==guidCode);
        if(c!=null)
            return;
        var client = new ClientAccountAccess(){GUID=guidCode};
        db.AddToClientAccountAccesses(client);
        db.SaveChanges();
    }
}

Then you will only insert it if it do not already exists

If you need to remove it before creating the object. You can do this:

private static void SetAccessCode(string guidCode)
{
    using (EPOSEntities db = new EPOSEntities())
    {
        var c= db.ClientAccountAccesses.FirstOrDefault(f=>f.GUID==guidCode);
        if(c!=null)
        {
            db.ClientAccountAccesses.DeleteObject(c);
            db.SaveChanges();
        }
        var client = new ClientAccountAccess(){GUID=guidCode};
        db.AddToClientAccountAccesses(client);
        db.SaveChanges();
    }
}

If you can update the object you can do something like this:

private static void SetAccessCode(string guidCode)
{
    using (EPOSEntities db = new EPOSEntities())
    {
        var c= db.ClientAccountAccesses.FirstOrDefault(f=>f.GUID==guidCode);
        if(c==null)
        {
            c=new ClientAccountAccess();
            db.AddToClientAccountAccesses(client);
        }
        c.GUID=guidCode;
        db.SaveChanges();
    }
}

Upvotes: 1

BLoB
BLoB

Reputation: 9725

Try something like this...

bool doesItExistAlready = (from caa in db.ClientAccountAccesses
                           where css.id == guidCode
                           select caa).Any();

if (doesItExistAlready)
{
    // Delete old record
    db.DeleteObject(PUTIDENTIFIERHERE);
}

// Add new record
ClientAccountAccess client = new ClientAccountAccess();
client.GUID = guidCode;
db.AddToClientAccountAccesses(client);

Upvotes: 1

Related Questions